Load Time History Research Articles

Development of design typhoon profile for offshore wind turbine foundation design in Southern China

For offshore wind development in Southern China, typhoon represents the extreme environmental loading condition to be considered in the design of the turbine structures. For the geotechnical design of the foundations, it is specified by the design code that the effect of cyclic loading on the soil strength and stiffness must be considered. This necessitates the complete time history of loads on the foundation experienced during a design typhoon. Idealised storm profiles with staged mean wind speeds and significant wave heights are commonly used as input to time-domain simulations to generate the foundation load history. However, no such design typhoon profile is provided in the Chinese design standard which creates considerable difficulty and uncertainty in the design process. In this paper, the methodology and the rationale that were applied to derive the design typhoon profiles for an offshore wind project in Guangdong province are presented. The wind and wave characteristics generated by typhoon are described in detail and the implications for the foundation design are discussed. To demonstrate application of the proposed typhoon profile, a case study for the ULS design of a suction bucket jacket is presented.

Study on multidimensional and multipoint seafloor spatial ground motion simulation under an ice-water layer and the dynamic response of a cross-sea bridge

A combined ice-water reflection coefficient is developed to measure the effect of saltwater and floating ice on seabed ground motions to explore the effect of floating ice on seafloor ground motions. The combined reflection coefficient is made up of three parts: the reflection coefficient of the seawater layer, the transmission coefficient of the water layer, and the reflection coefficient of the ice layer. The combined reflection coefficient analyzes the reflection, transmission, and refraction pathways of seismic waves from the soil layer to the water layer, then to the ice layer and air, and then reflects the attenuation principle of seismic waves in an ice-water layer based on the mechanical parameters of the soil layer, water layer, ice layer, and air. The spatial coherence effect, traveling wave effect, and local site effect are then addressed using the trigonometric series method, and the ice-water layer combined reflection coefficient is utilized to analyze the influence of offshore complex sites on seafloor spatial ground motion. Under the floating ice and seawater layer, an artificial synthetic approach of multidimensional multipoint spatial ground motion is described. The random ice load time history was artificially produced using the ice load spectrum theory and the recorded sea ice parameters. The random response of a long-span cable-stayed bridge is investigated under the combined action of seafloor spatial ground motion and random ice load, and the structural responses of the bridge and tower vary substantially under the combined action of ground motion and ice load.

Development and Validation of a Dynamic Abdominal Pressure Twin Sensor Finite Element Model

<div>Some anthropomorphic test devices (ATDs) currently being developed are equipped with abdominal pressure twin sensors (APTS) for the assessment of abdominal injuries and as an indicator of the occurrence of the submarining of an occupant during a crash event. The APTS is comprised of a fluid-filled polyurethane elastomeric bladder which is sealed by an aluminum cap with an implanted pressure transducer. It is integrated into ATD abdomens, and fluid pressure is increased due to the abdomen/bladder compression due to interactions with the seatbelt or other structures. In this article, a nonlinear dynamic finite element (FE) model is constructed of an APTS using LS-PrePost and converted to the LS-Dyna solver input format. The polyurethane bladder and the internal fluid are represented with viscoelastic and isotropic hypoelastic material models, respectively. The aluminum cap was considered a rigid part since it is significantly stiffer than the bladder and the fluid. To characterize the APTS, dynamic compression tests were conducted on a servo-hydraulic load frame under displacement control and held at the peak compression to allow for stress relaxation prior to slowly releasing the compression amount. The initial peak pressures and loads were 15–17% above the level observed at a 10-second hold period with 50% of the decay occurring within 300 ms. The material properties are identified using an inverse method that minimizes the difference between measured and predicted load and pressure time histories. Further, the bio-fidelity static specifications of the APTS manufacturer are used as a basis to identify the quasi-static material parameters. This approach resulted in a reasonable match between physical test data and model-simulated data for dynamic compressions of 10 mm and 15 mm (~50% compression). Additional compression tests are conducted at two compression levels (5 and 10 mm) and at four load offset configurations for use in the model validation. The FE model was used to predict peak pressure responses within approximately 10% error at full-load capacity and achieved CORA ratings >0.99 for the pressure time history. The proposed inverse method is expected to be generally applicable to the component characterization of other models and sizes of APT sensors.</div>

The Least Squares Time Element Method Based on Wavelet Approximation for Structural Dynamic Load Identification

Dynamic load identification is a commonly used and quite important approach to obtain the excitation loads of structures in engineering practice. In this paper, a novel dynamic load identification method combining the least squares time element method (LSTEM), wavelet scaling function and regularization method is proposed, which performs a better accuracy and a stronger anti-noise ability. It decomposes the time history of dynamic load into a series of time elements, and approximates the load profile at each time element using wavelet scaling functions. In order to balance the accuracy and efficiency for load identification, an optimal wavelet resolution is then determined. Simultaneously, the least squares time element model is derived which establishes the forward model for computing the wavelet coefficient. Finally, the wavelet coefficients for dynamic load identification are accurately and stably solved by implementing regularization. By this method, on the one hand, the wavelet scaling function and LSTEM improve the identification accuracy, and on the other hand, the integral process in the least squares operation gains the anti-noise ability for the load identification. A numerical example of a roof structure and an experiment of a composite laminate are studied and verify the effectiveness of the proposed method.

Impact load identification and localization method on thin-walled cylinders using machine learning

In this paper, a novel impact load identification and localization method on actual engineering structures using machine learning is proposed. Three machine learning models, including a gradient boosting decision tree (GBDT) model based on ensemble learning, a convolutional neural network (CNN) model and a bidirectional long short-term memory (BLSTM) model based on deep learning, are trained to directly identify and locate impact loads according to dynamic response. The GBDT model and the CNN model can reversely identify force peak and location of impact loads. The BLSTM model can reconstruct the time history of impact loads. The method is verified on a thin-walled cylinder with obvious nonlinearity. The result shows that the method can accurately identify impact loads and its location. The characteristics of the three models are compared and the influence of structural boundary conditions on the accuracy of identification is discussed. The proposed method has the potential to be applied to various engineering structures and multiple load types.

Joint parameter-input estimation for digital twinning of the Block Island wind turbine using output-only measurements

This paper presents a recursive Bayesian inference framework for digital twinning of an offshore wind turbine (OWT) in the Block Island Wind Farm (BIWF), the first commercial offshore wind farm in the U.S. with jacket substructure. The framework employs a window-based extended Kalman filter (EKF) to jointly estimate the dynamic input loads and unknown model parameters of the finite element (FE) model of the turbine using sparse output-only measurements. The estimation of input loads on the OWT is critical for fatigue life estimation, foundation monitoring and control strategy. In the proposed joint estimation algorithm, unknown input time histories are divided into overlapping windows and the current window of inputs is concatenated with uncertain model parameters to form an augmented state vector. To account for the uncertainty about wind direction and misalignment between wind direction and the turbine yaw angle, two independent horizontal wind load time histories in X and Y directions are estimated at the nacelle level. A numerical validation study is first performed in which wind loads of the OWT are simulated using the multi-physics platform FAST, and structural vibration responses are generated using the FE model in OpenSees. The window-based EKF is implemented using the simulated measurements, and the estimations of structural stiffness as the updating model parameter and input loads are observed to have high accuracy. The proposed algorithm is then validated using in-situ measurements on one of the OWT in BIWF. To investigate the effectiveness and robustness of the method under different environmental and operational conditions, four cases are considered in which the turbine is operating at the rated rotor speed (region 3 of power generation), below the rated rotor speed (region 2), idling rotor state (region 1 or no power), and region 4 beyond cut-out wind speed. Accurate predictions of acceleration and strain data are obtained using the proposed algorithm, and the estimations of model parameter are consistent and close to their nominal value under different conditions. These results from numerical and experimental studies validate the proposed window-based EKF for joint parameter-input estimation and digital twinning for long-term structural health monitoring of the OWT.

Probabilistic fatigue life assessment of steel rail-bridge in dual response surface framework

A new probabilistic fatigue life assessment (PFLA) procedure is proposed considering dynamic effects of train loading, possible enhancement of axle load, and uncertainty there-in. In conventional PFLA, Monte Carlo simulation (MCS) is used to simulate stochastic load. Thereafter, rainflow counting method is used to obtain mean stress ranges. However, it is well-established now that only mean stress range may not depict the detailed stochastic nature of train axle load time-histories. Moreover, such MCS-based PFLA is computationally demanding for real-life complex structures, and routine implementation of it is quite troublesome due to dearth of skilled engineers in advanced fatigue analysis and interface software. To circumvent this, the proposed PFLA procedure resorts to dual response surface method (DRSM), which yields explicit equations for mean as well as standard deviation of stress range. Using these equations, the proposed approach directly relates fatigue life with the input factors (train speed, axle load, etc.) through an excel spreadsheet without requiring MCS. The effectiveness of the proposed procedure is elucidated through an existing steel railway bridge in India. The accuracy of the approach is also validated with four other steel bridges practically failed in fatigue. The results show that the proposed PFLA is in excellent agreement with the most accurate direct MCS-based PFLA, and the practical data obtained from failed steel bridges; whereas, the conventional moving load analysis-based deterministic fatigue life assessment approach yields significantly deviated results. Also, the proposed DRSM-based PFLA approach is observed to be computationally more efficient than the conventional direct MCS-based PFLA.

A numerical assessment of variable saturation of the upper layers on the ground borne vibrations from underground trains: A case history

Ground borne vibrations generated by the passage of underground trains may change over time due to objective causes, such as increasing weight and speed of trains or ageing of the infrastructure components, as well as a variation in the dynamic response of the soil surrounding the tunnel. Among the possible causes of changes in the soil dynamic response, its hydrologic state has been seldom investigated. In this contribution, the role played by the conditions of the soil above the water table is addressed, starting from a case history in the city of Milano. Two-dimensional plane strain numerical models have been developed for the infrastructure. The models were calibrated on the results of two geophysical investigations performed at the same site in the city centre, but at two different times, which allowed distinguishing different dynamic responses. The system was excited by a synthetic load time history, matching a reference dynamic load spectrum included in Italian recommendations. Limitations of using this input on a 2D plane strain model were assessed by comparing the computed vibrations with experimental acceleration records collected on the tunnel. The results of the two numerical models are compared with those of a simulation performed assuming fully dry conditions above the water table. Overall, the set of analyses shows that even small changes in the dynamic response of the soil, interpretated as a consequence of variable saturation, may result in a change of a few decibels in the acceleration levels. Much larger accelerations are predicted on average with the simpler dry model, clearly showing the advantages of a more accurate modelling strategy.

A Study on Creep-Fatigue Evaluation of Nuclear Cladded Components by ASME-III Division 5

In this paper, a study on creep-fatigue evaluation on the cladded nuclear component subjecting to low pressure and high temperature services is carried out. To do this, the codes and standards presented by ASME-III Division 5 are reviewed, and a detailed evaluation procedure is presented step by step for practical applications. As an example of practical design application, a molten salt reactor vessel with a cladding thickness of 10% of the base material thickness is designed and four representative operation cycle types are established. The stress cycle types based on finite element stress analysis are determined from the operation cycle types having coolant temperature and pressure time history loads, and results of the creep-fatigue evaluation are described step by step according to the evaluation procedure. From the result of the creep-fatigue evaluation, it is found that the creep-fatigue evaluation for reactors such as molten salt reactor, sodium-cooled reactor, and so on, which are operated at low pressure and high temperature, is dominated by thermal loads. In this study, the effects of the cladding material and the thermal stresses on the creep-fatigue evaluation are investigated. In addition, as one of the design options to reduce the thermal stresses, the thickness of the exampled vessel is reduced, and the calculated creep-fatigue values are compared with the acceptance creep-fatigue envelope criteria of the ASME-III Division 5.

Measurement and application of walking models for evaluating floor vibration

For light and long-span structures, human-induced vibration may present a serviceability issue. To study the vibration serviceability problem, it is important to have a better understanding on human-induced forces, such as walking. To this end, the load-time histories of walking excited by 25 test participants were measured using a force-measuring plate. Totally, 300 walking force–time histories were recorded; and the peak load factors were compared in detail. The correlation analysis shows that there is a weak correlation between the three directional components of walking load, i.e., the walking component can be modeled independently. Then, the Fourier series functions for walking were derived; and the relationships between the dynamic loading factors, phase angles and the duration time Tp of single-step walking were developed, giving the forcing functions. The load-time history extension method was used to establish the forcing function for continuous walk. Lastly, the proposed continuous walking model was validated with the test and finite element results.

Performance-based wind design for tall buildings: Review and comparative study

A brief review and state of the art for Performance-Based Wind Design (PBWD) has been presented to provide researchers with clear historic literature on the development of PBWD concepts. The literature clearly emphasizes the main differences between Performance-Based Seismic Design (PBSD) and Performance-Based Wind Design and the challenges incurred. The study presents a brief description of the current prescriptive approaches and the challenges and limitations to their use and the broad wide range of research areas in Performance-Based Design (PBD). It also highlights the nonlinear inelastic response studies for structures subjected to wind loads and the envelope performance for structures. Immense efforts have been made to develop the PBD concepts, and similar to PBSD, the PBWD approach has shown great potential, yet it has several uncertainties that need further investigation. Those PBWD approaches will have a tangible effect on the design concepts and consequently on the design of the fast-growing tall buildings for more resilient communities subjected to extreme wind events and accordingly, more economic designs. Wind tunnels and reliable Computational Fluid Dynamics (CFD) analysis can help in developing concepts and provide a dynamic load time history which will greatly help in Performance-Based Wind Engineering. The incorporation of field data on non-structural elements' performance during non-synoptic wind incidents (i.e., hurricane and thunderstorm events) into the simulation and analytical models is still under development and shows high potential and promising research outcomes that would help in developing more accurate damage evaluation and serviceability satisfaction. A comparative case study was also presented for the responses under wind and seismic forces. From the study, it can be concluded that PBWD has potential in some cases especially if the governing wind case is the across-wind case, where a significant reduction in base shear and moment values (∼50%) was observed when the building stiffness decreased. On the other hand, when the along-wind load is the governing load case, decreasing the building's stiffness has led to higher base forces (∼100% increase in the responses). However, further investigation is needed to study different aspect ratios and shapes and include more frequency ranges.

Effects of traffic load amplitude sequence on the cracking performance of asphalt pavement with a semi-rigid base

ABSTRACT The propagation of cracks in in-service asphalt pavements is closely related to the complicated traffic loading patterns over time. However, typical traffic-related variables capture only the overall traffic level without being able to account for the load-time history. Therefore, this study aims to investigate the effects of traffic load sequence on the cracking performance of asphalt pavement from both field and laboratory perspectives. A load amplitude sequence (LAS) index was developed to characterize the traffic loading sequence in the field. Two machine learning (ML) algorithms, namely artificial neural network (ANN) and random forest regression (RFR), were applied to correlate the LAS index with field pavement cracking performance. The two-block semi-circular bending (SCB) test was developed to characterize the non-linear fatigue damage accumulation of asphalt mixtures. It was found that heavier traffic loads in early stages are detrimental to the long-term pavement cracking performance. The LAS index plays a crucial role in the prediction and development of pavement cracks. The laboratory test results reveal that a loading sequence starting with a higher stress may shorten the fatigue life and vice versa. The outcomes of this study may contribute to a better understanding of the traffic loading characterization of in-service asphalt pavements.

Low Velocity Impact Response of Reinforced Concrete Flat Slabs

Background Dimensions of the reference concrete slab are 1950x1950x100 mm subjected to drop-weight impact loading. Objective A comprehensive parametric study was performed to examine the influence of many parameters on the RC slabs. Method From the viewpoint of cost and time savings, a three-dimensional finite element is a very good tool to predict the real behavior of the structural elements. Result and Discussion Results showed that the use of CFRP strips enhance the impact behavior of the slab. Contrarily, the existence of opening led to a dramatic decrease in the dynamic capacity of RC slabs with stress concentration around the openings. Furthermore, changing the shape of the impactor showed a significant effect on the peak impact load as well as the ultimate deflection at impact instant. Conclusion In the scope of this paper, the response of RC slab with top and bottom reinforcements exposed to drop-weight impact loading was inspected. Time histories of impact loads and deflections were presented in detail based on ABAQUS/ Explicit analysis. The findings presented in this paper can be presented as follows: 1. The FE models show a good correlation with the experimental data. Consequently, the proposed finite element models are efficient and economical tool to explorer the effect of many parameters on the performance of RC slabs subjected to drop-weight impact load. 2. The numerical simulation confirmed that using externally bonded CFRP strips has more influence on the peak deflection of the reinforced concrete slab than the recorded impact force. 3. Comparing to the flat shape of the impactor, the hemispherical and curved shape impactor can produce large penetration depth at the impact zone with higher plastic deformations in the concrete slab. However, the flat impactor produced higher deflection at the impact instant. 4. As the radius of the impactor increases, both the duration time and the peak impact force are increased. This is because of the higher contact area was obtained when the flat impactor (infinity radius of curvature) was used as compared to other impactors. 5. Due to decreases in RC slab stiffness, the presence of openings (regardless of their shape) has considerably increased deformations in concrete especially around perimeter of the openings extended to the nearby support. 6. It has been found that the eccentric impact loading causes higher plastic deformations than the concentric one.

A computational method for the load spectra of large-scale structures with a data-driven learning algorithm

For complex engineering systems, such as trains, planes, and offshore oil platforms, load spectra are cornerstone of their safety designs and fault diagnoses. We demonstrate in this study that well-orchestrated machine learning modeling, in combination with limited experimental data, can effectively reproduce the high-fidelity, history-dependent load spectra in critical sites of complex engineering systems, such as high-speed trains. To meet the need for in-service monitoring, we propose a segmentation and randomization strategy for long-duration historical data processing to improve the accuracy of our data-driven model for long-term load-time history prediction. Results showed the existence of an optimal length of subsequence, which is associated with the characteristic dissipation time of the dynamic system. Moreover, the data-driven model exhibits an excellent generalization capability to accurately predict the load spectra for different levels of passenger-dedicated lines. In brief, we pave the way, from data preprocessing, hyperparameter selection, to learning strategy, on how to capture the nonlinear responses of such a dynamic system, which may then provide a unifying framework that could enable the synergy of computation and in-field experiments to save orders of magnitude of expenses for the load spectrum monitoring of complex engineering structures in service and prevent catastrophic fatigue and fracture in those solids.

Determination of the parameters of material models using dynamic indentation test and artificial neural network

Stress-strain curves of materials normally change with strain rate and temperature and are normally defined by material models. In this study, a new technique was developed for determining the constants of material models. This technique was based on dynamic indentation test, numerical simulation using Ls-dyna code and artificial neural network. An indenter of tapered shape was shot against the materials as the target by a gas gun. The experiments were carried out for four strain rates and four temperatures. The target was made of pure copper. The penetration depth-time and load-time histories were captured by a LVDT and a piezoelectric load-cell, respectively and the load-penetration depth curve (P-h) was obtained. This curve is characterized by five parameters which are determined for each indentation test. On the other hand, the indentation test was simulated using Ls-dyna hydrocode. From the simulations, the P-h curves were obtained using Johnson-Cook (J-C) and Zerilli-Armstrong (Z-A) material models and the characterizing parameters of the numerical P-h curves were also identified. Finally, an artificial neural network (ANN) was trained by the numerical P-h curves parameters as the input and the constants of J-C and Z-A models as the output. The trained neural network was then tested by the experimental p-h curves parameters as the input and the constants of J-C and Z-A models as the output. Moreover, a number of dynamic compression tests were performed using the well-known Split Hopkinson Bar at the same strain rates and temperatures used for indentation tests and the stress-strain curves of material were obtained. A reasonable agreement was observed between the stress-strain curves predicted by neural network and the Split Hopkinson Bar. The proposed method does not need sophisticated instrumentation and in fact, the load-time and indentation depth-time histories are directly converted to stress-strain of material using an artificial neural network.

Transient hydrodynamic coefficients for a single DOF underwater manipulator of a square cross-section

Drag and added inertia coefficients for an underwater manipulator of revolute joints are time and shape dependent. This study proposes an extension of the method to determine transient hydrodynamic coefficients, which was originally developed for a single degree-of-freedom (SDOF) underwater manipulator of a cylindrical arm, for the arm of a square cross-section. This method is based on the normalization of coefficients using the dimensionless distance traveled by the centroid of water displaced by the arm. This results in simple approximation functions independent of kinematic conditions and dependent only on the dimensionless distance traveled. Surrogate model creation via machine learning methods requires many data sets obtained as a result of experiments or numerical simulations. The proposed normalization simplifies and speeds up the process of creating metamodels for drag and added inertia torques for SDOF manipulators because only a few time histories of the hydrodynamic load are required for regression. The results of this study indicate that the method based on such a normalization can be applied to a SDOF underwater robotic arm of a square cross-section with good accuracy, thus widening the scope of the original method.

Fatigue Life Analysis of the Submarine Rudder Stock Mechanism at Arctic Low Temperatures

Under the action of Arctic low temperatures and long-term alternating loads, the fatigue life of the submarine rudder stock mechanism is severely tested. In this paper, the research method of the static strength analysis and fatigue life analysis of the submarine rudder stock mechanism is proposed by combining multibody dynamics, the finite element method, and tests. Based on the three-dimensional model and the motion law of the rudder stock mechanism, a multibody dynamic model is established, and the time history loads of each node of the mechanism are obtained. According to the working temperature range of the submarine rudder stock mechanism in the Arctic, low-temperature tensile tests are carried out. Based on the experimental data, the finite element model is built, and static analysis is carried out. Using the S–N static fatigue design method, fatigue simulation analysis is performed by using nCode DesignLife. The analysis results show that the fatigue life of the submarine rudder stock mechanism decreases significantly when the temperature is reduced from 0 °C to −60 °C. This method can provide a reference for submarine design and life model establishment in the Arctic environment.

Closed-Form Derivation of Optimum Tuned Mass Damper Parameter Based on Modal Multiplicity Criteria

It is presently established that properly designed tuned mass dampers (TMD) systems can effectively control the vibrations induced due to the wind and/or the seismicity. The TMD is one of the most used passive control systems in high-rise structural systems in an era of recent developments. The optimum parameters for the damped system to date require a numerical search technique or shootout technique, which is the trial-error method, of-course add complexity in selecting parameters obtained at optimality conditions. The study of optimum parameters based on modal multiplicity criteria showcases the complete closed-form solution, independent to another optimum parameter. The parameters presented in this study solely depend on structural damping and mass ratio. The derived optimum parameters are compared with the existing parameters in this field. This study also investigates parametric uncertainty for structural configuration under the harmonic excitation. To confirm its robustness under random vibration, various earthquake time history loads are applied to study the effect of structural displacement and acceleration response. In the end, the energy concept is deployed to explain how effectively the optimum TMD parameters help to reduce the kinetic energy, damping energy, strain energy, and input energy.

An experimental study of wave-in-deck loading and its dependence on the properties of the topside structure

This paper concerns the largest and arguably the most threatening wave loading component experienced by a broad range of offshore structures. It arises when an incident wave crest exceeds the elevation of the underside of the deck structure, leading to direct wave-in-deck (WID) loading. The extent of this loading may be limited to the partial submergence of some of the lowermost deck beams, or could involve the large-scale inundation of the entire deck area. Either way, very large loads can arise which must be taken into account when assessing the reliability of the structure. In an earlier contribution Ma and Swan (2020) provided an extensive laboratory study exploring the variation of these loads with the properties of the incident wave. The present paper describes a second stage of this experimental study in which the variation of the WID loads with the properties of the topside structure is addressed. Specifically, it considers the porosity, position and orientation of the topside relative to the incident wave conditions, and seeks to explore both the variations in the maximum load and the loading time–history resulting from these changes.Given the highly transitory nature of a WID loading event, coupled with the fact that the problem is governed by flow conditions at, or very close to, the instantaneous water surface, the loading process is driven by an exchange of momentum from the wave crest to the topside structure. A recently developed WID load model, based on exactly these arguments (Ma and Swan 2020), is used alongside the laboratory data to provide a break-down of the load into its component parts. This provides an enhanced physical understanding of the resulting load time–history. The first part of the study is based upon an idealised generic topside structure, allowing a systematic variation in key parameters, particularly porosity. The second part addresses a realistic topside structure demonstrating the practical relevance of earlier work. Taken together, the analysis clearly establishes the importance of the topside porosity, clarifies the spatial effects associated with the evolution of a large ocean wave beneath the plan area of a structure and explains the unexpected occurrence of impact-type loading on topside structures having a high porosity. Most importantly, the paper highlights those properties of a topside structure which must be incorporated if the WID loads are to be accurately predicted.

Low velocity impact penetration response of foam core sandwich panels with face sheets

Foam aluminum sandwich panels have potential applications in many fields because of their excellent performance. This study aims to explore the low velocity penetration dynamic response of foam sandwich panels. Based on the experimental results, a three-stage penetration model is established. Based on the principle of energy conservation, minimum potential energy and accumulating damage theory, the load and displacement time history, energy absorption and initial failure mode of the sandwich panel during penetration are predicted theoretically. The theoretical prediction results are compared with the experimental results, showing that the predicted failure load and deformation are within 10% of the experimental data. This paper provides an analytical method for studying the deformation failure mode and energy absorption mechanism of metal foam sandwich panels, which is helpful to improve the efficiency of metal foam sandwich panels in design.